MongoDB replacing an array

[neilwatson]

Hello,

I'm trying to use the Perl MongoDb module to extract a list from mongo, alter the data and replace the original list. The replace operation has gone wrong. I have tried this code:

$col->update(
          { "host" => $host },
          {
                     '$set' => { "timestamp" =>  [ @new ] }
          },
          { 'multiple' => 1, 'safe' => 1 }
) || die "$!";

This does not seem to work as the list is emptied by the update. What have I done wrong?

[Khen1950fx]

This is just a general idea. You'll probably need to adjust the validation options in order for it to work.

#!/usr/bin/perl

use strict;
use warnings;
use MongoDB;
use DateTime;

my $today = DateTime->now;
my $stamp = DateTime->now->set(
    'timestamp' => $today->day,
);

my $database = '/tmp/collection';
$database->update(
    {'host' => '127.0.0.1'},
    {'set' => {"timestamp" => 'new'}},
    {'multiple' => 1, 'safe' => 1}
);

[neilwatson]

New quoted without an array '@'? In my original example '@new' is any array.

[Mr. Muskrat]

I can't find any documentation to indicate that there is any sort of validation that happens during an insert or update of a generic column.

[chchow]

I believe this is correct: $col->update( { "host" => $host }, { '$set' => { "timestamp" => \@new } }, { 'multiple' => 1, 'safe' => 1 } ) || die "$!"; It should be a array ref instead.

[Mr. Muskrat]

I don't use MongoDB so bear with me. Has this sort of update worked before? I ask because it looks like you update timestamps with a DateTime object, not an array, as shown in the MongoDB module's DataTypes documentation section on Dates.

[neilwatson]

Timestamp is name of an array in a JSON inside a MongoDB database. I want to replace that entire array with a new one. My backup plan is to empty the array in MongoDB and then insert a new one.

[Mr. Muskrat]

And you're sure that @new is not empty at the point of the insert? Have you tried printing out its contents to be sure?